Internet access machine only

I'm looking for a low-cost device that would connect to my home wireless
network (802.11b/g) so that I can browse the Internet, I don't need it to do
anything else. It needs to be portable or at least mobile (ie: small enough
to fit on a chair, screen embedded). I would even go for a wired solution if
none else exist.

I've looked all around the web for something like it, but the closest thing
that I found was the Sidekick from T-Mobile. But it connects cellular, so no
good.

Please Help Me!